Lameness control is a measure for lowland flocks which aims to establish the level of lameness and implement a programme to reduce its incidence. The flock must be assessed five times during the year at the following time frames: during May/June; July/August; prior to mating (August to September/October); at least once between mating and lambing; and finally at any other time that the flock owner sees as delivering the best benefit. Scald

The number of sheep treated at the time of assessment must also be recorded, along with the product used and any other lameness preventative measures. An extensive guide on implementing a lameness control programme can be found at www.farmersjournal.ie.

First step

The first step in implementing a lameness control programme is to establish the cause of lameness. Each year, significant time and expense is invested into treating a disease which has often been misdiagnosed. The six main causes of lameness, along with a description of the characteristic signs and a brief recommendation for treatment, are underlined below.

Routine foot paring of hooves was recommended in the past, but this approach is no longer advised. If foot trimming is required, hooves should not be over-pared, with the clippers disinfected between each hoof to prevent the risk of disease spreading.

CODD

Lame sheep should also be isolated from the flock, with the exception of a case of scald where routine foot bathing is used to address the issue. The lame sheep should be kept isolated and only return to the flock once you are satisfied they have recovered.

Likewise, purchased sheep should be quarantined and receive the necessary precautionary treatment to prevent the risk of importing disease issues. The main area of concern here is importing CODD, as once it gets on to a farm, it is very hard to eliminate it.

Culling

Animals should be marked, so that repeat offenders can be identified for culling, as it is these sheep that generally end up giving the most problems. You should also avoid retaining replacement progeny from these persistently lame sheep.

Maintaining records in the scheme action record book will allow you to see if an improvement is being made, with the general target of keeping lameness at a level of less than 5% of the flock.

Prevention is certainly better than cure with lameness and regular foot bathing will help to keep any issues at bay. Getting sheep accustomed to running through a footbath when carrying out tasks such as dosing or drafting lambs will pay huge dividends in preventing issues from getting a chance to establish. This is especially the case in treating scald before it gets a chance to progress to footrot.

Footrot

Grazing management

Grazing management can also play a role. For example, footrot bacteria only survive on pasture for two weeks. Therefore, adequate treatment followed by grazing on clean swards can greatly aid in reducing lameness issues.

Vaccination can also play a key role in reducing the incidence and should be used strategically along with an overall control programme. There is rising pressure coming on all livestock systems regarding antibiotic use.

While antibiotic treatment is often vital in getting on top of an outbreak, antibiotics should be used strategically and not as a routine measure in controlling lameness.

Footbathing advice

The variable weather and continuous change in ground conditions and grass growth rates could give rise to an increase in the incidence of scald in lambs. Early intervention will improve the success of treatment and help keep lamb performance on track. There are numerous footbathing products on the market, with copper and zinc sulphate remaining the most commonly used products. These should be diluted at a rate of 10%, while the recommended strength for another commonly used product formalin is 3%.

Sheely hoof

Where footbathing to prevent issues, sheep can be run through the footbath, while, if treating issues, sheep may need to be stood in the footbath for a couple of minutes. Drafting off lame sheep for a longer stand in the footbath is a good way to improve the success of treatment.

Formalin is more severe on sheep and young lambs in particular should not be retained standing for an excessive length in footbath solution. Take care also to only use in a well-ventilated area and to take necessary precautions when handling.

Sheep should also be foot bathed where possible on a fine day, with feet as clean as possible. Ideally, sheep should run through a water bath first to reduce the level of contamination in the foot bath solution.

Main causes of lameness

Scald

  • Caused by bacteria present in soil and faeces with infection occurring through damaged skin.
  • Identifiable by a red/pink inflammation between the hoof claws with a white or grey paste like scum on top.
  • Treatment can include antibiotic sprays, antibiotic injections and footbathing.
  • If left untreated, it can progress to footrot.

    • Footrot

  • Footrot is a bacterial infection usually following scald. The bacteria can survive on pasture for a couple of weeks. Infection risk and disease spread is greatest in mild weather or housing in damp underfoot conditions at high stocking rates.
  • Its symptoms are grey coloured scum/pus between the hoof horns which also exhibits a characteristic strong odour.
  • The hoof horn or hoof shell can start to separate away from the shell and can start to lift away if the disease establishes.

  • Treatment includes footbathing, antibiotic sprays or injections.
  • Prevention includes footbathing, culling persistent offenders, selecting replacements with no history of disease and adequate quarantine procedures.

    • CODD

  • CODD is often mistaken as footrot. The main difference is the infection occurs at the top of the hoof or coronary band (area where hoof meets the leg).

  • Like footrot there is a grey pasty scum plus there can be some bleeding but there is no characteristic smell.

  • In severe infections it is not unusual for the hoof horn or hoof shell to fall off.
  • The disease is very painful and will significantly affect performance.

  • Veterinary advice should be sought if CODD is suspected.
  • Injectable antibiotics or antibiotic footbaths can be administered by vets.

    • Toe granuloma or strawberry foot

  • Toe granuloma gets the name ‘strawberry foot’ from its appearance. A piece of circular shaped tissue grows out on the bottom of the hoof.
  • The most common cause of infection is excessive hoof trimming where the soft part of the hoof tissue is excessively cut (blood should not be drawn) into and damaged.

  • The flesh is very sensitive to bleeding and painful.

  • The ailment is difficult to treat and frequently requires veterinary advice.

  • Despite treatment, sheep may still not recover and may require culling.

    • Hoof/toe abscess

  • A toe abscess occurs where the hoof tissue is damaged.
  • This can cause an infection resulting in the development of an abscess at the top of the hoof where it meets the coronary band.

  • The condition is painful and sheep will be lame.

  • Treatment can be carried out with antibiotic sprays or injectable antibiotics.

    • Shelly hoof

  • Shelly hoof is a condition of the hoof that results in the wall of the hoof separating and lifting away from the hoof.
  • The animal may not appear very lame in normal conditions but may become lame if walking on uneven or hard ground or stone yards etc. This can result from dirt, stones etc lodging between the hoof and the lifted hoof horn area.
  • Unlike other lameness diseases, the cause is unknown with hoof damage thought by vets to be a contributing factor.
  • Treatment usually includes pairing away the lifted section of the hoof to expose a new layer underneath. Mineral/vitamin imbalances have been reported to be linked with the disease.

    • Pictures: Courtesy of Jasmeet Kaler and Laura Green, University of Warwick.